Semiconductor device

1. A semiconductor device having a wafer level chip size package (WL-CSP) structure, comprising: a semiconductor substrate having an integrated circuit formed thereon; a plurality of electrode pads formed on the semiconductor substrate, being intended for input and output of signals between the integrated circuit and an external circuit; at least one rewiring layer which includes rewiring formed adjacent to the plurality of electrode pads so as to be integral with the semiconductor substrate; and a plurality of external electrodes which is formed on the rewiring layer so as to be integral with the semiconductor substrate, the plurality of external electrodes being connected to the plurality of electrode pads via the rewiring, the external electrodes making connection terminals for the external circuit, wherein the plurality of external electrodes include a first group of external electrodes arranged along an edge of the semiconductor substrate and a second group of external electrodes arranged inside the first group of external electrodes, and wherein the plurality of electrode pads are arranged between the first group of external electrodes and the second group of external electrodes, and are each connected to an external electrode included in either the first group of external electrodes or the second group of external electrodes via the rewiring wherein the integrated circuit comprises: input/output circuits to be connected to the plurality of electrode pads, the input/output circuits being arranged along the edge along which the first group of external electrodes are arranged such that at least a part of the circuits overlaps an area where the first group of external electrodes are arranged; and a functional circuit arranged near the center of the semiconductor substrate; and the plurality of electrode pads are arranged between the input/output circuits and the functional circuit, wherein the input/output circuit and the first group of external electrodes are isolated from each other by an insulating layer.

2. The semiconductor device according to claim 1 , wherein the plurality of external electrodes have a minimum spacing generally equivalent to an integral multiple of a minimum spacing of the plurality of electrode pads.

3. The semiconductor device according to claim 1 , wherein the first and second groups of external electrodes are arranged systematically at regular intervals.

4. The semiconductor device according to claim 1 , further including an insulating film formed over the electrode pads, the insulating film having openings at locations above the electrode pads, and wherein the rewiring is formed on the insulating film.

5. The semiconductor device according to claim 4 , further including an sealing resin layer formed on the insulating film, wherein the rewiring and each of the external electrodes are connected via a post built in the sealing resin layer.

6. A semiconductor device having a wafer level chip size package (WL-CSP) structure, comprising: a semiconductor substrate having an integrated circuit formed thereon; a plurality of electrode pads formed on the semiconductor substrate, being intended for input and output of signals between the integrated circuit and an external circuit; at least one rewiring layer which includes rewiring formed adjacent to the plurality of electrode pads so as to be integral with the semiconductor substrate; and a plurality of external electrodes which is formed on the rewiring layer so as to be integral with the semiconductor substrate, the plurality of external electrodes being connected to the plurality of electrode pads via the rewiring, the external electrodes making connection terminals for the external circuit, wherein the plurality of external electrodes include a first row of group of external electrodes, arranged linearly, and along an edge of the semiconductor substrate, and a second row of group of external electrodes arranged linearly in parallel with the first row of group of external electrodes, and wherein the integrated circuit comprises: input/output circuits to be connected to the plurality of electrode pads, the input/output circuits being arranged along the edge along which the first row of group of external electrodes are arranged such that at least a part of the circuits overlaps an area where the first row of group of external electrodes are arranged; wherein some of the plurality of electrode pads are located in an area interposed between the first and second rows of groups of external electrodes, and are each connected to one of the external electrodes in either the first or second row of group of external electrodes by means of the rewiring, and wherein the input/output circuit and the first row of group of external electrodes are isolated from each other by an insulating layer.

7. A semiconductor device according to claim 6 , wherein the first or second row of group of external electrodes have a minimum spacing generally equivalent to an integral multiple of a minimum spacing of the plurality of electrode pads.

8. A semiconductor device having a wafer level chip size package (WL-CSP) structure, comprising: a semiconductor substrate having an integrated circuit formed thereon; a plurality of electrode pads formed on the semiconductor substrate, being intended for input and output of signals between the integrated circuit and an external circuit; and at least one rewiring layer which includes rewiring formed adjacent to the plurality of electrode pads so as to be integral with the semiconductor substrate; and a plurality of external electrodes which is formed on the rewiring layer so as to be integral with the semiconductor substrate, the plurality of external electrodes being connected to the plurality of electrode pads via the rewiring, the external electrodes making connection terminals for the external circuit, wherein the plurality of external electrodes include a first row of group of external electrodes, arranged linearly and along an edge of the semiconductor substrate, and a second row of group of external electrodes arranged linearly in parallel with the first row of group of external electrodes, and wherein the integrated circuit comprises input/output circuits to be connected to the plurality of electrode pads, the input/output circuits being arranged along the edge along which the first row of group of external electrodes are arranged such that at least a part of the circuits overlaps an area where the first row of group of external electrodes are arranged; wherein the plurality of electrode pads include a first row of group of electrode pads arranged linearly, and a second row of group of electrode pads arranged linearly in parallel with the first row of group of electrode pads, and wherein each of the electrode pads in the first and second row of group of the electrode pads are respectively connected to one of the external electrodes in the first and second row of group of external electrodes by means of the rewiring, and wherein the input/output circuit and the first row of group of external electrodes are isolated from each other by an insulating layer.